Answer:
4 mph
Step-by-step explanation:
The average speed of an object is given by the total distance covered by the time taken:
where
d is the total distance covered
t is the time taken
in the first part, the person runs for 0.4 hours at a speed of 7 mph, so the distance covered in the 1st part is
Then the distance covered in the second part is 
, so the total distance is
(1)
The total time elapsed is 0.4 hours (first part) + 0.8 hours (second part), so
So we can write the average speed as
(1)
We want the average speed to be 5 mph,
v = 5 mph
Therefore we can rearrange eq.(1) to find d2:
And therefore, the speed in the second part must be
4b. Laura has a 12-foot ladder. The safety instructions recommend the
base of the ladder be placed 4 feet from the base of the wall. How highwill the ladder be able to reach on the wall? WRITE YOUR ANSWER AS A SIMPLIFIED RADICAL. (HINT: Use the abbreviation sqrt to mean "square root of." For example an answer might look like 5sqrt3, and be read "five times the square root of 3".)
First of all gall, the end is NOT an exponent, its the unit of measurement for finding the area (thats square units)
Heres the answer:
31.5 square units.
Explanation:
The formula for the area of a triangle is bh/2
The formula for the area of a triangle is bh
(Use this formula and try to find the real explanation)
Answer:
95%
Step-by-step explanation:
About 95% of the area is within two standard deviation in standard normal distribution. This can be explained by finding the probability within 2 standard deviation using standard normal distribution.
P(z1<Z<z2)=P(-2<Z<2)
P(-2<Z<2)=P(-2<Z<0)+P(0<Z<2)
P(-2<Z<2)=0.4772+0.4772
P(-2<Z<2)=0.9544
Thus, About 95% of the area is between z2 and z2
The exponent of x in 4x would be 1.
